ON5 Company

The fifth element: the energy efficiency

ON5 stands for the “On the 5th element of Energy” conveying the vision of its founders to promote the transition for businesses and individuals towards a world where Energy savings would improve our lives. Aiming at the 5th element of consuming no energy we would become less dependent of the existing four sources or energy which are the atom, the sun, the moon and the earth.

These four elements are indeed the sources of all the existing types of energy mastered so far by mankind (nuclear, photovoltaics, wind power, biomass, tidal energy, hydroelectricity, geothermal power and fossil fuels). The 5th Element is the cheapest, the one than does not pollute and the backbone of a successful energy efficiency approach.

ON5 is the international brand funded by the French cleanweb company called in French “Economie d’Energie” (stands for Energy Savings).


The Team

There are 100 of us working at ON5 COMPANY GROUP. We have all different background from young talented individuals to senior experienced energy professionals. We have one common passion all fully engaged personally with the company’s purpose.

We are now expanding in Europe (Italy, Spain) and now UK under the brand name ON5


Myriam Maestroni CEO


Franck Bruneau Vice-President


Christelle Spiry Sustainable Development Director


François Châtelain Marketing Director


Rosa Uriona ON5 Company Spain Director


Nicolás Diez Perez IT Director


Anne Creusy Finance Director


CÉDRIC PAQUET sales director


Pauline Richard Technical and Operations Director


Antoine Mersch Controller


DOMINIQUE RAJZBAUM Market Services Director


More than 100 people from different backgrounds


Foundation e5t



The purpose of the e5t Foundation is to become the one stop think tank that will influence operators to act upon: “Energy Efficiency, Saving energy and our local communities”

E5t is an open think-tank where everyone who is working and/or is concerned by the challenges and opportunities could share and collaborate with peers and other practitioners, researchers and business contacts.

The vision of the foundation to help identify and address the challenges we all face in relation to the decrease of stocks fossil energies and their now recognized detrimental effect on the environment. E5t foundation will contribute to generate and communicate about innovative solutions to these climate change energy dependency related issues.


1. To engage the know-how and skills of all the energy industry practitioners (enterprises, politicians, public servants, students, teachers and consumers). At our Summer Event (last over 2 days in August in La Rochelle in France), each invited speaker will be given the opportunity to present their work for 10 minutes individually or within a round-table discussion.

2. In order to promote and raise the profile and media visibility of innovative ideas and businesses in Energy Efficiency, we have created the Energy Innovation Awards for Local Communities. These Awards will incentivize the launch of new projects and initiatives that will directly or indirectly contribute to adapt to the shift to renewable energy.

Applicants need to apply via our website on www.e5t.fr and choose one of the three following categories :

·         Innovation

·         Efficiency: Implementation and tangible impact

·         Positive Impact on local communities

The 3 winners of E5t Territorial Innovation Prize for the 2016 edition were:

  1.  Navya technologies, with a fleet of 100% autonomous electrical cars.
  2.  Comwatt, the project which promote self-consumption of the electricity produced by private individuals through photovoltaic solar panels, associated with an original and innovative system that allows to use and stock energy for daily uses, thanks to optimization algorithms.
  3.  Carabati, tiles made in France which favours manufacturing techniques allowing to reduce environmental footprint.

A Special Mention Prize was awarded to Blue Planet Challenge, a program set up to allow children and young people to discover in a playful manner the notion of sustainable development through an online platform, educational kits for teachers and activities for schoolchildren.

The Jury’s Favourite Prize was for “L’arbre à vent” (Wind Tree), a wind power generator with natural and innovative design that insure its efficiency in urban areas.


  • The first summer university conference of the 5et Foundation in La Rochelle took place on the 28th and 29th of August 2013 under the title “Energy, Energy Efficiency and Local Communities.’’ With over 130 attendees and 45 scheduled talks, the event was a huge success.
  • The second conference under the title “Energy transition, Innovation and Local Communities, “on the 27th and 28th of August 2014, was an even greater success with the participation of over 230 people attending 50 talks.
  • The third conference has exceeded expectations. On the 26th and 27th of August 2015, under the title “In the run up to COP21 – are France and Europe good examples?” The event had closed to 280 participants and 60 speakers.
  • The 4th edition took place on August 24th and 25th, 2016 in La Rochelle. This last edition gathered 450 participants and 70 speakers, invited to reflect on “the low carbon growth and its paradoxes, from the Paris Agreement to the solutions of the COP22.” 

To obtain all the information: http://www.e5t.fr/




Tailored energy efficiency solutions for businesses and individuals.
More information about ON5 UK


A comprehensive program designed to incentivise and engage energy consumers at home, at work and using transports to become “eco-actors”. The program reaches out to employees, customers, suppliers, students and pupils in schools.


Digital solutions coupled with a range of operational services to help home owners renovate their property. Renovation works become simpler, clearer and affordable.


Digital solutions combined with a range of operational services designed to help any business, institution or organisation save costs and reduce their energy consumption.


Our comprehensive and flexible offering to implement successfully your energy efficiency strategy


Business Case: Bpifrance



  • To develop citizen consciousness among its employees.
  • To unit its teams, using dynamic and fun learning and commitment.
  • To promote not only environmentally friendly actions and behaviors but also social actions.


  • ON5 COMMUNITY: the web platform VOTRE GESTE AU COMPTEUR  is an innovative and fun tool designed to increase awareness of Bpifrance employees around positive actions for the planet and the environment (eco-actions) and allow them to commit toward social actions (socio-actions)
  • The platform allow Bpifrance to federate a community of committed and responsible employees, and to promote energy savings.

Business Case: BNP Paribas

home biz


  • Business committed in assisting its customers in the Energy Transition, reducing its carbon footprint and that of its customers.
  • Business looking to become more innovative and interesting in doing of Energy Efficiency a driver for competitiveness.
  • Business in need to offer new services to its clients to stay competitive and increase turnover.


  • ON5 BIZ: New digital and operational offer designed to help SMEs, clients or not of BNP PARIBAS, on line and off line, to carry out and optimize their energy efficiency projects.
  • ON5 HOME: New digital and operational offer designed to help BNP PARIBAS and HELLO BANK individuals clients, on line and off line, to carry out and optimize their renovation work projects.
  • Both offers include a complete chain of services: from EPC’s and audits, to technical solutions and funding services.

Under construction


Regulation in spain


Energy Efficiency National Fund


Alternative measures


Regulation in France


Needs more information ?
We will advise


Energy poverty


Energy passport


Needs more information ?
We will advise


Regulation in Italy


Needs more information ?
We will advise


Regulatory environment


ON5 Company


Contact UK

ON5 Company LTD, UK

Anne-France Kennedy

+44 78 10 893 029

Impact Hub King's Cross - 34b York Way, King's Cross London
More information

Contact FR

Economie d'Energie SAS, France

Aurélie Gosselin

+33 181 69 30 00

67 Boulevard Bessières, 75017 Paris

Contact ES

ON5 Company Spain SL, Spain

Raquel Herrero

+34 677 444 290

Paseo de Recoletos, 7-9 5º, 28004 Madrid

Contact IT

ON5 SRL, Italy

Giuseppe Truglio

+39 33 93 887 806

Corso Matteotti 1, 20121 Milano

ON5 Company